In a MIMO communication system, a transmitter transmits data through multiple transmitting antenna (NT) and a receiver receives data through multiple receiving antenna (NR). The binary data to be transmitted is usually divided between the transmitting antennae. Each receiving antenna receives data from all the transmitting antennae, so if there are M transmitting antennae and N receiving antennae, then the signal will propagate over M×N channels, each of which has its own channel response.
MIMO wireless communication systems are advantageous in that they enable the capacity of the wireless link between the transmitter and receiver to be improved compared with previous systems in the respect that higher data rates can be obtained. The multipath rich environment enables multiple orthogonal channels to be generated between the transmitter and receiver. Data can then be transmitted over the air in parallel over those channels, simultaneously and using the same bandwidth. Consequently, higher spectral efficiencies are achieved than with non-MIMO systems.